ADACOR: a collaborative production automation and control architecture

Manufacturers are under enormous pressure to comply with market changes and the continual shortening of product life cycles. An analysis of the ADACOR collaborative manufacturing control architecture from the point of view of the Collaborative Manufacturing Management paradigm shows how ADACOR (adaptive holonic control architecture for distributed manufacturing system) supports integration and extension across the manufacturing value chain.     

Preparation and characterization of chitosan based micro networks: Transposition to a prilling process

Beads of chitosan (CS) crosslinked network and of chitosan/poly(ethylene oxide) (CS/PEO) semi‐interpenetrating network (semi‐IPN) were prepared by a dropping technique and characterized. PEO content in the beads of semi‐IPN was determined by gel permeation chromatography. CS crosslinking ratio was evaluated qualitatively by ATR‐FTIR spectroscopy and quantitatively by UV spectrophotometry. After drying in a fluidized bed apparatus, a monodisperse population of well individualized, spherical, and smooth particles was obtained. It was shown that bead collapsus during the drying stage was avoided thanks to the chemical crosslinking of CS chains. By the prilling, or laminar jet break‐up technology, production at a larger scale was also achieved. This process allowed the formation of a row of well calibrated drops of polymer solution under the influence of a vibration. Polymer solution characteristics, particularly viscosity, constituted a critical factor in the feasibility of the prilling process. Transposition of the formulation was managed through the optimization of process parameters such as vibration frequency, amplitude, and flow rate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2550–2558, 2004     

Stenting after optimal lesion debulking (sold) registry. Angiographic and clinical outcome

BACKGROUND: Coronary stenting has reduced restenosis in focal de novo lesions, but its impact has been less pronounced in complex lesion subsets. Preliminary data suggest a role for plaque burden in promoting intimal hyperplasia after stent implantation. The aim of this study was to test the hypothesis that plaque removal with directional atherectomy before stent implantation may lower the intensity of late neointimal hyperplasia, reducing the incidence of in-stent restenosis. METHODS AND RESULTS: Seventy-one patients with 90 lesions underwent directional atherectomy before coronary stenting. Intravascular ultrasound-guided stenting was performed in 73 lesions (81%). Clinical success was achieved in 96% of patients. Procedural complications were as follows: emergency bypass surgery in 1 patient (1.4%), who died 2 weeks later; Q-wave myocardial infarction in 2 patients (2.8%); and non-Q-wave myocardial infarction in 8 patients (11.3%). None of the patients had stent thrombosis at follow-up. Angiographic follow-up was performed in 89% of eligible patients at 5.7+/-1.7 months. Loss index was 0.33 (95% CI, 0.26 to 0.40), and angiographic restenosis was 11% (95% CI, 5% to 20%). Clinical follow-up was performed in all patients at 18+/-3 months. Target lesion revascularization was 7% (95% CI, 3% to 14%). CONCLUSIONS: Directional atherectomy followed by coronary stenting could be performed with good clinical success rate. Also, these data point to a possible reduction in angiographic restenosis and a significant reduction in the need for repeated coronary interventions. Therefore, a randomized clinical trial seems appropriate to test the validity of this approach.     

Color Doppler echography in the study of pseudo-occlusion of the internal carotid

The differentiation of pseudo-occlusion from complete internal carotid artery occlusion may have important clinical consequences for patients with the former tend not to benefit from reconstructive surgery. The Authors report a case in which color-Doppler duplex-scanner revealed a persisting string-like lumen that was not demonstrated by angiography. The Authors believe that ultrasonography may in future permit the reliable differentiation of pseudo-from complete carotid occlusion, thereby reducing the need for angiography.     

Macro- and micro-cellular porous ceramics from preceramic polymers

Macrocellular and microcellular SiOC open cell ceramic foams were fabricated from a preceramic polymer. Macrocellular foams, with a cell size ranging from about 100–600 μm and a bulk density ranging from about 0.25–0.58 g/cm³, depending on the processing parameters, were fabricated using a direct foaming approach. Microcellular foams, with a cell size of about 8 μm, were fabricated using poly(methyl methacrylate)microbeads as sacrificial templates. The bulk density ranged from about 0.31–0.48 g/cm³, depending on the amount of microbeads in the starting material. The compression strength of the foams increased with increasing relative density, and microcellular foams possessed a 2–5 times higher crushing strength than macrocellular foams of similar density.     

Evaluation of electromagnetic power deposition in a spherical multilayer head in the near field of a linear antenna

The canonical problem of the radiation of an elementary dipole close to a stratified sphere representing a simplified model of human head is investigated in this paper. The proposed approach is a flexible method of investigation about the influence on Specific Absorption Rate (S.A.R.) evaluation of tissue dielectric parameters and geometry as well as a useful tool to test numerical codes. The solution of the electromagnetic (e.m.) problem is achieved in a closed form; results highlight the position of maximum S.A.R. values and their dependence on frequency: for particular layer thicknesses and dielectric parameters, the maximum absorption can occur in the frequency range of cellular phones.     

High prevalence of serum cryoglobulins in multitransfused hemophilic patients with chronic hepatitis C

The prevalence, clinical relevance, and risk factors of serum cryoglobulins in hemophilic patients with chronic hepatitis C virus (HCV) infection are unknown. We studied 135 consecutive hemophilic patients (median age, 31 years; range, 10 to 69 years) with chronic hepatitis C, exposed to the virus for 10 to 41 years. A total of 67 patients were coinfected with the human immunodeficiency virus (HIV), and 3 (2%) had signs of cirrhosis. Serum samples were tested for the presence of cryoglobulins, hepatitis B virus (HBV) markers, including HBV-DNA by hybridization assay, and antibody to HCV by enzyme immunoassay (EIA). Serum HCV-RNA was tested by polymerase chain reaction and typed with a hybridization technique. Samples were also tested for antitissue antibodies, immunoglobulins, rheumatoid factor, and C3 and C4 proteins of complement. Forty-two hemophiliacs (31%) circulated cryoglobulins (median levels, 166 mg/L; range, 66 to 480) predominantly type III (62%; and 29% type II). None of the patients had clinical signs or symptoms of systemic vasculitis. Cryoglobulinemic patients had more often serum HCV-RNA (95% v 80%, P < .05), rheumatoid factor (20% v 6%, P < .05), higher levels of IgG (2,354 +/- 682 mg/dL v 1,928 +/- 557 mg/dL, P < .0005) and IgM (323 +/- 226 mg/dL v 244 +/- 243 mg/dL, P < .05), and lower levels of serum C4 (19 +/- 8 mg/dL v 24 +/- 8 mg/dL, P < .05) than patients without cryoglobulins. The risk of producing cryoglobulins was greater for 114 patients circulating HCV-RNA than for 21 nonviremic patients (odds ratio [OR] = 4.9, 95% confidence interval [CI] = 1.1 to 22.0) and for the 31 patients with longer exposure to HCV (more than 26 years) than for the 24 patients with shorter (17 years or less) exposure (OR = 4.4 95% CI = 1.1 to 18.0). In conclusion a large number of multitransfused hemophiliacs with chronic HCV infection circulated serum cryoglobulins but none had clinical signs or symptoms of vasculitis. The risk of developing cryoglobulins parallels the duration of exposure to HCV.     

Localized fibroma: a rare tumor of pleural origin

Localized fibroma represents a rare entity arising from the pleura. Currently its histogenesis and clinical behaviour are still controversial. A case of a 64-year-old male is here presented; clinical and histopathological features are then discussed on the basis of a review of the Literature. At present, an en-bloc resection of the tumor, including wide margins of the surrounding lung tissue, seems to be the most appropriate surgical choice.     

An electromigration and thermal model of power wires for a priori high-level reliability prediction

In this paper, a simple power-distribution electrothermal model including the interconnect self-heating is used together with a statistical model of average and rms currents of functional blocks and a high-level model of fanout distribution and interconnect wirelength. Following the 2001 SIA roadmap projections, we are able to predict a priori that the minimum width that satisfies the electromigration constraints does not scale like the minimum metal pitch in future technology nodes. As a consequence, the percentage of chip area covered by power lines is expected to increase at the expense of wiring resources unless proper countermeasures are taken. Some possible solutions are proposed in the paper.